600MW中间再热空冷凝汽式汽轮机通流部分设计

主要总结和分析了600MW中间再热空冷凝汽式汽轮机通流部分的特点,重点介绍了机组通流部分设计的先进性和空冷末级叶片的气动设计特点.结果证明,机组的经济性和安全性均达到先进水平,机组推出后受到用户关注.     

1 000MW超超临界空冷汽轮机研究

超超临界1 000MW等级的空冷汽轮机高效、节能、有利于环保,适用于煤炭资源丰富但水资源匮乏的地区。该机组在成熟的湿冷1 000MW超超临界汽轮机和空冷汽轮机基础上模化设计而成。超超临界汽轮机的关键技术以及空冷汽轮机的关键技术问题已基本解决。通过调整高、中、低压通流面积和选用一只合适的末叶片来适应空冷机组进汽量大、运行范围大的特点。该机组技术成熟,安全可靠。     

空冷汽轮机末级680mm叶片的开发

空冷汽轮机组在电力市场上所占的份额越来越大,哈尔滨汽轮机厂有限责任公司对空冷汽轮机组进行了冷端优化,设计背压由15kPa降为11kPa。为提高机组效率,需要设计一个比原有空冷末级620mm叶片排汽面积更大、余速损失更小的空冷末级叶片。     

首台国产两排汽600MW等级超临界直接空冷汽轮机的研制

介绍了600MW超临界两缸两排汽空冷汽轮机的参数及结构,从通流设计、高中压模块、阀门设计、轴袭击滑销系统等几个方面介绍了机组的技术特点.     

空冷机组给水泵配置的研究

根据某工程的设计条件,在300MW空冷机组给水泵配置研究的基础上,以600MW空冷机组为重点,针对空冷机组的特点,分析给水泵配置有关的技术问题,讨论汽动给水泵不同的冷却方式,研究不同给水泵配置对主机通流能力和满发背压、机组热效率、设备可靠性和灵活性等方面带来的影响。按照该项目的设计条件,从技术经济上对汽泵和电泵方案进行详细比较,提出空冷机组给水泵配置的推荐意见。同时对1000MW级空冷机组进行定性分析,供业主在决定给水泵配置方式时参考。     

高背压大流量空冷汽轮机低压级组叶片设计及优化

开发出一套基于一维热力设计、准三维设计分析和优化、全三维流场分析以及叶片结构设计、强度、振动分析的开发体系。通过以空冷低压级组为实例进行设计,结果表明通过该设计开发体系,能够方便可靠地进行汽轮机通流和结构的设计和优化,这对汽轮机设计和改型具有很好的实用意义。     

直接空冷系统排汽管道特性研究

为了研究直接空冷机组排汽管道内水蒸汽的流动特性,采用CFD技术,对某台200MW直接空冷机组排汽管道内的水蒸汽流场进行了三维数值模拟.根据数值计算结果,在直接空冷大直径排汽管道内的弯头和三通等处安装导流叶,不仅有利于减小工质在管道内的流动阻力和实现管道内工质的均匀分布,而且有利于提高直接空冷系统的整体热效率.     

CFX-TASCflow在汽轮机通流设计中的应用

从应用CFX—TASCflow的角度介绍了哈尔滨汽轮机厂有限责任公司(简称哈汽)在汽轮机通流部分全三堆流场设计的应用成果，典型介绍了分流结构叶片、叶片汽封、多级叶片的三维流场计算和新一代亚临界600MW汽轮机高压缸通流气动设计。结果证明，利用CFX—TASCflow能详细地分析三维粘性场各种参数的特性及变化，进一步研究流场中的各种流动情况，控制好流场中的相关参数，合理地设计出高效三维叶片，大大提高了通流效率。     

空冷汽轮机低压排汽面积选择和变工况特性分析

根据我国西北某地区的典型环境温度对600MW直接空冷机组的低压末叶片进行优化,得到合理的低压排汽面积,同时根据末级叶片的设计特点对其变工况特性进行分析,从而对620mm末叶片的变工况性能有一定了解。分析结果表明,设计背压为15kPa.a时,末叶片采用620mm比较合适;采用专用强化叶型、控制反动度、控制攻角等方法的620mm末叶片可以有效保证空冷机组变工况安全高效运行。     

对直接空冷机组空冷单元内环形喷雾增湿系统的数值讨论

应用气水两相流的传热传质理论,建立了600MW直接空冷机组空冷凝汽器喷雾增湿三维数学模型,利用CFD软件对空冷单元内喷雾增湿系统进行数值摸拟,分析了喷嘴圆形布置及喷雾方向对喷雾增湿效果的影响,得到了使机组真空提高幅度最大的喷嘴最佳布置方式,对该类型机组空冷单元的喷雾增湿系统的设计安装有一定参考意义.     

空冷汽轮机的末级叶片

针对空冷机组的特殊性，分析了末级叶片的设计特点。并介绍了HTC设计的600MW空冷机组末级叶片的最佳高度选择、结构特点、气动性能和强度振动性能。     

Effect of Cooling Water Flow Path on the Flow and Heat Transfer in a 660 MW Power Plant Condenser

The effect of the cooling water flow path on the flow and heat transfer in a double tube-pass condenser for a 660 MW power plant unit was numerically investigated based on a porous medium model. The results were used to analyze the streamline, velocity, air mass fraction and heat transfer coefficient distributions. The simulations indicate that the cooling water flow path is important in large condensers. For the original tube arrangement, the heat transfer with the lower-upper cooling water flow path is better than that with the upper-lower cooling water flow path. The reason is that the steam cannot flow into the internal of upper tube bundle and the air fractions are higher in the upper tube bundle with the upper-lower cooling water flow path. An improvement tube arrangement was developed for the upper-lower cooling water flow path which reduced the back pressure by 0.47 kPa compared to the original scheme. Thus, the results show that the tube arrangements should differ for different cooling water flow paths and the condenser heat transfer can be improved for the upper-lower cooling water flow path by modifying the tube arrangement.     

Numerical investigation on the flow field of an axial flow fan in a direct air‐cooled condenser for a large power plant

The flow field of an axial fan in a direct air‐cooled condenser for a large power plant is modeled numerically. In order to improve the efficiency of heat exchange of the air‐cooled condenser, methods of increasing the rotational velocity of the fan and laying out the guide blade at the outlet of the fan are adopted. Results show that increasing the rotational velocity of the fan can effectively increase the flux of the fan, and can improve the efficiency of an air‐cooled condenser; laying out the guide blade at the fan outlet can ameliorate the flow field in an A‐flame. This causes the rotational kinetic energy to change into static pressure at the fan outlet, so the ability of the heat exchange of the air‐cooled condenser is improved. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21027     

用于汽轮机排汽冷却的蒸发式冷凝器模型及性能分析

蒸发式冷凝器兼具传热性能好和节水的优势,在大型动力系统冷却中具有广阔的应用前景。建立了蒸发冷凝器的理论分析模型,提出了蒸发式冷凝器用于冷却小型汽轮机排汽的设计方案;获得了喷淋水温度、空气和蒸汽的焓值在冷凝器内沿程的变化规律,并对喷淋水量、配风量和空气温度等影响冷凝器性能的影响因素进行了分析。研究结果对蒸发式冷凝器在火力发电行业的应用具有参考意义。     

冲动式135MW机组中压缸通流部分优化设计

介绍了冲动式中间再热优化型135MW机组中压缸通过气动优化设计,如叶型的优化、通道的光滑以及超高的考虑等方面的优化,使中压缸效率得到了改善。本机组现已在天生港电厂投运,中压缸效率提高～2.0%,达到了预期的目标。     

汽轮机凝汽器冷却管束设计要领分析

更新老的凝汽器设计概念，对凝汽器运行进行分析，使汽轮机组运行的经济性得以充分地发挥。降低热耗、消除凝结水的过冷现象、提高真空、合理地选材和冷却面积最有效地合理利用是当今改造、设计，提高中、大型汽轮机组热效率的内容之一。尤其是对众多已运行了二、三十年的老机组的凝汽器改造或更新更为重要。尽管不同凝汽器制造厂家不同的结构型式，均面临同样的问题。针对凝汽器冷却管束的一些相关内容，从设计角度给予了全面分析。     

火电站直接空冷凝汽器积灰监测

火电站直接空冷凝汽器积灰是影响传热性能的重要因素,研究直接空冷凝汽器积灰对传热性能的影响规律并提出监测措施具有重要意义。通过分析汽轮机背压与汽轮机排汽量、冷却空气流量、凝汽器传热系数、凝汽器总传热面积以及环境温度之间的关系,得到了空冷凝汽器在维持汽轮机排汽量和冷却空气量不变时,汽轮机背压和传热系数之间的关系以及凝汽器积灰对汽轮机背压的影响。研究表明:凝汽器积灰会导致凝汽器传热系数降低,汽轮机背压升高,机组运行经济性下降。设计工况下,当蛇形翅片扁平管结构凝汽器积灰厚度达到1.2 mm时,汽轮机背压将增加50%左右。通过监测空冷机组运行过程中汽轮机背压的变化,可预报积灰的程度,为直接空冷凝汽器清洗提供一定的理论依据。     

多级空气透平试验台的设计与开发

透平通流技术的研发通常采用数值和试验分析相结合的方法,空气透平试验更加接近叶栅实际的工作条件,使我们可以获得透平机械叶栅通道内气体流动的更真实的物理现象,为设计开发提供可靠的试验数据。文章对东方汽轮机有限公司的空气透平试验台系统组成、参数选择、本体结构特点、关键参数的测量进行了阐述,对试验台设计中的关键技术问题进行了分析说明。     

The use of CFD for predicting and optimizing the performance of air conditioning equipment

This paper reports on the use of CFD for predicting and improving the performance of a rooftop AC unit. The current work considered the hydrodynamic and thermal fields on the air flow side of the unit with exact modeling of fans and heat exchangers. This is in addition to predicting condensation on cooling coils. Because only the air flow side is considered, the evaporator and condenser compartments are decoupled and the solution in each section is established separately. In the evaporator compartment the flow is solved as a two-phase flow (gas and liquid) with the gas phase being composed of two species (dry air and water vapor). In the condenser section however, the flow is treated as a single phase flow. The exact modeling of heat exchangers and fans increased the grid size and computational cost, but resulted in realistic results and reliable model. A total of 31 million control volumes are used to model the evaporator and condenser sections. Results indicate the presence of several recirculation zones in the evaporator compartment. Sensible and latent cooling capacities for several design conditions predicted by the model are in close agreement with available experimental data. The differences between the total capacities predicted by the model in the evaporator section and those reported experimentally are within 2.7% for all cases considered. Predictions in the condenser section resulted in a load that is only 0.00136% different than the one calculated using experimental data. To improve the performance of the unit, six different modified designs of the evaporator coil are developed and tested. The newly modified designs are based on changing the coil inclination angle and/or number of fins per unit length for the same coil height and surface area. One of the designs resulted in 6.18% decrease in the cooling capacity, while the remaining modifications increased the cooling capacity by values ranging between 2.17% and 8.6%.